The Built-Up roofing (BUR) and modified-bitumen (MB) systems are a low-slope, asphaltic roofing system popular among the commercial buildings because of the durability and sustainable characteristics. Popular for both new construction or roof replacement, these asphaltic roofing options are the reliable option because of the many layers that make up the asphalt system. Because of these layers, many contractors believe it is superior to singly-ply roofing systems.
Composed of asphalt and reinforced with either polyester or fiberglass, modified bitumen roofs are a blend of traditional and modern roofing technologies. Two different polymers are used to modify the membrane and impart greater elasticity and temperature flexibility. Since polyester fiberglass fortifies the roof system, it exhibits more strength and resistance to punctures and is typically installed in various layers to provide a multi tier protection system from water, extreme temperatures and wind uplift.
Modified Bitumen roof systems are typically installed as a 2-ply system and almost always installed fully adhered using several different methods. Some are installed using hot asphalt, self adhesives or cold adhesives, while others are installed using the torch method. Elite Roofing and Consulting professionals will assess your roof and suggest the best application method for your facility.
Built-up roof systems consist of multiple layers of felts, fabrics, or mats that are saturated with bitumen, either asphalt or coal tar pitch. The surface of the roof can have a gravel application, a mineral cap sheet or a weather resistant coating to help protect the bitumen and felts from premature weathering. BUR is one of the oldest low slop roof systems that are still applied to commercial roofs today.
Advantages of modified bitumen roofing are: